1. Field of the Invention
The present invention relates to heating, ventilating, and air conditioning systems and more specifically relates to a cabinet for housing air handling equipment.
2. Description of Related Art
Air handling equipment, such as blowers, heat exchangers, compressors, filters, etc., can help provide conditioned air to a comfort zone, such as a room or other designated area within a building. The conditioning of the air may include, but is not limited to, heating, cooling, humidifying, dehumidifying, filtering, ventilating, and various combinations thereof.
Usually a cabinet, such as a sheet metal enclosure, houses some or all of the air handling equipment. The cabinet usually provides a conduit that directs the airflow across the various pieces equipment inside the cabinet. In outdoor applications, the cabinet may also help shelter the equipment. For heating or cooling applications, the walls of the cabinet may be thermally insulated to minimize heat loss and help prevent condensation from collecting on the interior or exterior wall surfaces. An insulated door may also be needed to provide access to the equipment inside the cabinet.
Some pieces of equipment, such as the blower for instance, can be installed outside of the enclosure with ductwork placing the blower in fluid communication with the interior of the cabinet. Whether the blower is inside or outside the cabinet, the blower can be used to move the air across the rest of the air handling equipment. Depending on whether the blower discharges air into the enclosure or draws the air out, the blower may create positive or negative air pressure within the cabinet.
To prevent air from leaking between the interior and exterior of the cabinet, a gasket is usually installed around the periphery of the cabinet's access door. As straightforward as this may seem, designing an airtight, insulated hinged door for an air handling enclosure can become quite involved considering the numerous factors that may affect the design. The door, for instance, may need to swing inward for a positive-pressure cabinet and swing outward for a negative-pressure cabinet. Unforeseen obstructions at the installation site may dictate whether the door needs to be a right-hand or a left-hand swinging door. An air pressure differential between the cabinet's interior and exterior may crush the door's gasket, or the pressure may eventually cause the gasket to take a set or permanently deform in a compressed state. For insulated doors, the insulation may need to be sealed to protect the insulation from moisture.
Consequently, certain access doors for cabinets of air handling equipment may need to be custom-made for a particular application. This can be time consuming, expensive, and often impractical.